It was at the first Yearly Kos in Las Vegas that a prominent Dem staffer told me, "Obama's running." I don't think I quite believed it at the time, though I understood it would be game changing to some degree if true. I think that due to the extended primary season we've lost sight to some extent just how game changing this is.
Being at an Obama party with a substantial African-American presence, it really sunk in how much this is a "holy shit" moment. Whatever happens next, it is an historic moment.